He said he’d never touched a weapon un­til four months ago. But then rebels shot dead his father and his 17-year-old brother, send­ing him flee­ing to this dis­placed-per­sons site in search of refuge and re­venge.

“I took up my gun to kill the [rebels] who killed my father and brother,” the 29-year-old said, fid­dling with three bul­lets in his free hand. “I need to avenge the deaths.”

Zoumatchi’s thirst for vengeance led him to join a lo­cal “self-de­fense” mili­tia, which gave him a firearm and a role in the new­est chap­ter of a con­flict that has left thou­sands dead in this for­mer French colony. The vi­o­lence has per­sisted for four years de­spite ef­forts by the United Na­tions, hu­man­i­tar­ian groups and even Pope Francis to end the fight­ing.

Suc­cess­ful demo­cratic elec­tions early last year spurred hopes that the con­flict might fi­nally end. But clashes erupted again in Novem­ber. Since then, hun­dreds have died, and tens of thou­sands have been forced from their homes amid es­ca­lat­ing vi­o­lence be­tween the dozen or so armed groups con­trol­ling some 80 per­cent of the Cen­tral African Repub­lic. At­tacks are tak­ing on in­creas­ingly sec­tar­ian over­tones.

U.N. of­fi­cials have raised alarms about “early warn­ing signs of geno­cide.” Diplo­mats and re­lief work­ers say this im­pov­er­ished coun­try of about 4.6 mil­lion runs the risk of an all-out civil war, which would com­pound the hu­man­i­tar­ian cri­sis and cre­ate new se­cu­rity prob­lems in a re­gion al­ready grap­pling with ex­trem­ist groups such as Boko Haram.

The vi­o­lence be­gan when a pre­dom­i­nantly Mus­lim coali­tion of rebels called the Seleka swept to power in 2013 after killing and burn­ing their way through this ma­jor­ity Chris­tian coun­try. Mostly Chris­tian groups known as the anti-bal­aka formed to fight back. Many of the armed groups sub­se­quently splin­tered. The Seleka rulers were even­tu­ally re­placed by an in­terim gov­ern­ment, and a for­mer prime min­is­ter, FaustinAr­change Touadéra, be­came pres­i­dent last year in what many saw as a sign of progress.

An­a­lysts say the lat­est vi­o­lence is due in part to the new gov­ern­ment’s fail­ure to sat­isfy the armed groups’ de­mands for po­lit­i­cal rep­re­sen­ta­tion and amnesty.

“To get what they want, they need to in­crease the power of ne­go­ti­a­tion. And in or­der to in­crease the power of ne­go­ti­a­tions, they need to rep­re­sent a threat,” said Nathalia Dukhan, an an­a­lyst at the Enough Pro­ject, a Washington-based re­search group fo­cused on African con­flicts. “They in­creased their ca­pac­ity to harm.”

That hasn’t been hard to do in a coun­try where the cen­tral gov­ern­ment wields lit­tle power out­side the cap­i­tal, the army is in­ef­fec­tive and ill-equipped, and in­fra­struc­ture such as roads is lim­ited.

Ex-Seleka fac­tions are now fight­ing one an­other — in some cases team­ing up with their for­mer op­po­nents. Anti-bal­aka, fre­quently re­ferred to as “self-de­fense” groups, have ex­panded.

The cap­i­tal city of Ban­gui, guarded by U.N. peace­keep­ers, re­mains calm, but taxi­cab ra­dios blare the grow­ing list of hot spots across the coun­try: Zemio, Batan­gafo, Obo. In ad­di­tion to the in­ter­nally dis­placed — who now num­ber 600,000 — about 500,000 peo­ple have fled to neigh­bor­ing coun­tries since 2013, ac­cord­ing to the United Na­tions.

Ar­eas pre­vi­ously spared high lev­els of vi­o­lence now have be­come flash points, with the coun­try’s south­east of par­tic­u­lar con­cern. Some ex­perts say the with­drawal this past spring of U.S. and Ugan­dan forces po­si­tioned in the area to search for Joseph Kony, the rebel leader of the Lord’s Re­sis­tance Army, cre­ated a power vac­uum — one armed groups are look­ing to fill.

“Armed groups have taken over the whole of the coun­try,” said Joseph In­ganji, the U.N. hu­man­i­tar­ian agency’s chief of of­fice for the Cen­tral African Repub­lic.

There have been nu­mer­ous failed at­tempts to bro­ker peace, in­clud­ing a deal struck in June in Rome by rep­re­sen­ta­tives of the armed groups. Less than 24 hours later, new clashes killed dozens.

The man­date for the 12,000strong U.N. peace­keep­ing force in the coun­try ex­pires in Novem­ber, and Touadéra is among those call­ing for a re­newal and a troop in­crease. But peace­keep­ers are also in the crosshairs — 10 have been killed this year. Civil­ian an­i­mos­ity to­ward peace­keep­ers has grown, ex­ac­er­bated by a sex­ual abuse scan­dal and al­le­ga­tions of in­ac­tion in the face of at­tacks.

More than half the pop­u­la­tion is in need of hu­man­i­tar­ian as­sis­tance. But amid the surge in vi­o­lence, ac­cess to aid has sharply de­te­ri­o­rated. Eleven aid work­ers have been killed since the start of the year — mak­ing it one of the most dan­ger­ous places in the world for hu­man­i­tar­ian work. Aid com­pounds have been looted and at­tacked, prompt­ing many or­ga­ni­za­tions to pull back or limit their ac­tiv­i­ties.

In some parts of the coun­try, vil­lagers are holed up in churches and hos­pi­tals, un­able to ven­ture out for fear of be­ing killed. Food sup­plies in some places are run­ning low.

“The main risk is re­ally to come back to a con­flict like it was in 2013 . . . very close to a kind of civil war,” said Thibaud Le­sueur, an an­a­lyst for the In­ter­na­tional Cri­sis Group, a non­profit that seeks to re­solve vi­o­lent con­flicts. At the time, large num­bers of civil­ians were killed or raped, and scores of vil­lages were de­stroyed.

David Brown­stein, who as charge d’af­faires is the se­nior U.S. diplo­mat here, said it is im­por­tant to pre­vent a se­cu­rity vac­uum in a re­gion al­ready grap­pling with the Is­lamist ex­trem­ists of Boko Haram and, fur­ther afield, the Is­lamic State.

Be­cause of its ge­o­graph­i­cal po­si­tion, the Cen­tral African Repub­lic “plays a fun­da­men­tal role in ei­ther en­hanc­ing and pro­mot­ing regional sta­bil­ity, or, con­versely, if it’s weak­ened or failed, it could have a fun­da­men­tally neg­a­tive im­pact on regional sta­bil­ity,” he said.

Many say re­li­gion isn’t re­ally driv­ing the vi­o­lence — that armed groups are look­ing to gain power and to profit off re­sources such as di­a­monds and gold. But that doesn’t mean fight­ers aren’t ex­ploit­ing eth­nic and re­li­gious dif­fer­ences.

Stephen O’Brien, who un­til re­cently served as the U.N. hu­man­i­tar­ian chief, said after a visit in July to the Cen­tral African Repub­lic that “the early warn­ing signs of geno­cide are there,” with grow­ing eth­ni­cally and re­li­giously tar­geted at­tacks.

The sec­tar­ian ten­sion is ev­i­dent in Bria.

Just four months ago, fight­ing forced 40,000 civil­ians to flee their homes and set up makeshift shel­ters on the edge of a U.N. base.

“We Chris­tians don’t want to have prob­lems,” lo­cal anti-bal­aka leader Jethro Soukou said on a re­cent morn­ing. “It’s the Mus­lims that make the prob­lems.”

“They treat us like an­i­mals,” he said, voice near­ing a shout. “When they’re out on their pa­trols and see one of us, they kill him in the street.”

Months ago, a rare ma­chete tucked into a waist­band was the only sign of weaponry in the camp. To­day, men with guns slung over their backs roam the maze of tents.

Françoise Rene­heta had only re­cently ar­rived from a small village near Bria. Voice scratchy from ex­haus­tion, Rene­heta said loud booms had shat­tered her morn­ing 10 days ear­lier.

“I started to hear shots, weapons fir­ing,” said the 25-year-old. She said she dropped the man­ioc she’d been pre­par­ing for break­fast, grabbed her chil­dren and ran.

Rene­heta held no hopes of re­turn­ing to her village; she had heard their house was torched along with oth­ers.

She didn’t say so out­right, but many at the camp credit the anti-bal­aka within the perime­ter for en­sur­ing their safety. An­tibal­aka fight­ers scoffed when asked about the need to bear arms given the pres­ence of peace­keep­ers, say­ing the con­tin­gents don’t pro­tect the pop­u­la­tion.

That’s why mem­bers of the rag­tag band of fight­ers said they go on patrol, some­times leav­ing the site to com­bat the “Mus­lims” in town they con­sider a di­rect threat.

Not far down the red-dirt road, there’s a main drag of shops where armed men — “the en­emy” — stroll or laze un­der trees with AK-47s be­tween their knees.

On a re­cent af­ter­noon, Ab­dra­man Dji­a­bal­adin, who guessed he was in his 80s, stacked bro­ken branches in front of his house near the town’s cen­ter.

Three weeks ear­lier, he said, anti-bal­aka mem­bers had sur­rounded this neigh­bor­hood and opened fire.

“There were so many bul­lets that they broke the branches of the mango tree,” he said, adding that he sur­vived by fir­ing back.

He said he would not be driven from his home.

“We don’t have any en­e­mies other than the anti-bal­aka,” he said. “I need to stay and fight.”

CAS­SAN­DRA VINOGRAD/THE WASHINGTON POST

PHO­TOS BY CAS­SAN­DRA VINOGRAD/THE WASHINGTON POST

ABOVE: Jerry Zoumatchi, whose father and brother were killed by armed rebels, said he wants vengeance for their deaths. TOP: Dis­placed peo­ple in Bria wait for ra­tions from peace­keep­ing forces. About 40,000 refugees live in makeshift shel­ters there on the edge of a U.N. base.